For the transmission of information, use is customarily made of an RFID communication between a transponder and a reader in particular via a near-field communication (NFC) or BLUETOOTH® connection. The transponder, which may be passive, is firstly awoken by a reader interrogation signal, and a rectifier in the transponder makes it possible to tap off, from the received signal, a supply voltage for the operation of the said transponder. Generally once awoken, the transponder can transmit for example a constant information item, which is an identification number of the transponder or of the product or object on which it is placed. This constant information item is therefore transmitted by the transponder on request of the RFID reader in communication.
In customary RFID transponders, the transmission of data or of the constant information item is effected with mean bitrates of the order of a few hundred kbits/s. This requires fairly lengthy transmission of data and therefore relatively significant consumption. This does not in principle allow the use solely of the energy tapped off from an external auxiliary source connected to the transponder circuit to allow sufficient power supply until all the data have been transmitted, thus constituting a drawback.
In the case of a connection via BLUETOOTH®, a synchronization with the reader is firstly performed. Also, an unwieldy communication protocol, which is complicated and a heavy consumer of current, is used. Therefore, it is not conceivable to use such a communication via BLUETOOTH® for a passive or semi-passive transponder powered by extracting energy from an external energy source, thus constituting a drawback.
A transponder or portable RFID device can be placed on an object in motion or a person or an animal. The transponder can comprise sensors for performing measurements of various physical parameters of the object or of the person or animal. These measurements can be transmitted to a reader or base station for remote processing or use of the measurements. However, the transponder or the portable RFID device must be powered via a sufficient energy source so as to be able to transmit the measurements performed without overly heavy consumption, this being difficult to carry out via a transponder or portable device of the prior art.
It is possible to cite patent application WO 2012/125425 A1, which describes a portable device, in the form of a patch, furnished with various sensors. This portable device can be placed on a person to determine, by way of several sensors, various physiological parameters of the person (biorhythms). The measurements performed can be stored and transmitted to a processing station, which manages the measurements performed by the portable device on the person for a medical checkup for example. The portable device comprises a battery to provide the power supply required in order to obtain the various measurements via the sensors. However, this portable device cannot operate without the supply battery and its consumption is not reduced so as to perform measurements periodically and to be able to transmit the stored information to the processing station rapidly, thus constituting a drawback.